Device and method for transferring microstructures

ABSTRACT

A device and a method for transferring microstructures from a tool to a substrate which is to be structured. The device and method are intended to align the tool and the substrate in a mutually controlled manner. The device contains supports for the tool and the substrate which can be displaced in an opposing direction in relation to one another, resulting in an alteration of the distance between the tool and the substrate. A measuring system is provided which can be inserted between the supports, for measuring selected locations on at least one measuring plane. The direction of displacement of the supports is aligned vertically in relation to said measuring plane. The measuring system forms a fixed spatial relationship with the tool in a measuring position. The substrate can be aligned in relation to the tool. The method and device can be used for producing microstructured components.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The invention relates to the transfer of microstructures from a tool toa substrate which is to be structured, with supports for the tool andthe substrate which can be adjusted in relation to one another in adirection resulting in an alteration of the distance between the tooland the substrate.

b) Description of the Related Art

A device of this type is known, for example, from DE 196 48 844 C1.

For transferring microstructures, it is known to press a molding toolinto a moldable material, such as for example a layer of thermoplasticmaterial, preferably under a vacuum and at a temperature above thesoftening temperature of the moldable material and, as a result, toproduce three-dimensional structures with structure heights in the rangeof just a few nanometers up to several hundred micrometers.

A device suitable for this purpose, according to DE 196 48 844 C1, iscapable of compensating for variations in thickness of molding tools andof moldable materials used, while ensuring high dimensional stability,and of ensuring different molding depths.

The device includes a chamber with a chamber part which is fixed to theframework and a chamber part which is adjustable, in which chamber thesetting of the pressure and temperature conditions is linked toprescribed values of a force acting on the fixed chamber part.

It is disadvantageous in the case of this known device that the locationat which the structures are to be transferred into the moldable materialcannot be determined.

OBJECT AND SUMMARY OF THE INVENTION

It is therefore the primary object of the invention to ensure that thetool and the moldable material can be mutually aligned in a manner whichcan be monitored.

According to the invention, the object is achieved by a device fortransferring microstructures from a tool to a substrate which is to bestructured, with supports for the tool and the substrate which can beadjusted in relation to one another in a direction resulting in analteration of the distance between the tool and the substrate, in that,for measuring selected locations in at least one measuring plane, inrelation to which the direction of adjustment of the supports isdirected vertically, a measuring system which can be pushed in betweenthe supports and, when in a measuring position, is in a fixed spatialrelationship with the tool is provided, and in that the substrate can bedisplaced parallel to the measuring plane for alignment with respect tothe tool.

The support for the tool is contained in a first chamber part and thesupport for the substrate is contained in a second chamber part of aclosable chamber, in which the transfer of the microstructures takesplace by molding.

The chamber is advantageously designed as a vacuum chamber or can befilled with inert gas.

The measuring system includes various optical branches with image fieldsof different sizes, the magnification of a first optical branchpermitting easy searching for the locations to be selected and that of asecond optical branch permitting exact measurement of the selectedlocations in the measuring planes.

A transporting device which contains different drives for positions tobe moved to one after the other is provided for the pushing in of themeasuring system, a first drive undertaking the transport from a firstposition outside the chamber into a second position in the openedchamber and a second drive moving the measuring system into a positionaligned in relation to the tool. The measurement can be performedwithout hindering the molding.

The data ascertained are used for activating a device for displacing thesubstrate with respect to the tool which is contained in the secondchamber part. The device includes two sliding plates which lie one ontop of the other, are movable in relation to each other parallel to theplane of the substrate adjustment and of which an upper sliding plateserves as a chamber-closing element.

The upper sliding plate can preferably be clamped to the lower slidingplate.

The upper sliding plate can, furthermore, support a first part of aheating and cooling unit, on which a securing means for the substrate isfastened.

For changing the height of the chamber, the chamber may have side wallparts which provide a seal towards the outside and are themselvesadjustable in relation to one another in the direction of theadjustability of the chamber parts.

It is advantageous if the tool is enclosed on its circumferentialsurface by a cylindrical tool holder, which is fastened in the firstchamber part to a plate-shaped body.

The plate-shaped body may be in connection with a second part of aheating and cooling unit.

For removing the molded material from the tool, the tool holder may beenclosed at the lateral surface by a demolding tool, which isdisplaceable with respect to the tool holder in the direction of themutual adjustability of the supports for removing the substrate from thetool following the transfer of the microstructures.

To ensure great stability over time of individual systems of the device,the measuring system, the displacing device and the first chamber partmay contain channels for a temperature-controllable fluid.

For establishing the fixed spatial relationship between the measuringsystem and the tool, hooks for hanging on correspondingly shaped hooksof the first chamber part are fastened to the measuring system in theupper region of the latter.

It is also advantageous if the substrate comprises a supporting layerand a moldable material applied to the latter.

A tool for transferring structures into the moldable material may alsobe applied to the supporting layer.

The subject matter of the invention also includes a method fortransferring microstructures from a tool to a substrate which is to bestructured, with supports for the tool and the substrate which can beadjusted in relation to one another in a direction resulting in analteration of the distance between the tool and the substrate. Apositioning, required for the locationally exact transfer of themicrostructures, of the substrate which is to be structured with respectto the tool in a plane in relation to which the direction of adjustmentof the supports is directed vertically is ascertained by correctionvalues for the positioning, determined by the distance of themicrostructure from a mark on the substrate, being formed from measuredstructure positions of transferred microstructures on a first structuredsubstrate for at least one further substrate to be structured.

To increase the positioning accuracy further, on the first substrate thepositions of the marks may be additionally ascertained before and afterthe transfer of the microstructures for forming correction values forthe positioning.

If the positioning accuracy is to be improved still further, thepositions of marks on the substrate holder may be determined ascorrection values before a substrate is placed onto the substrateholder.

Finally, it is also advantageous if, after the molding of eachsubstrate, ascertained positions of the molded microstructures and ofthe marks are used as correction values for the positioning of thesubstrate which is to be respectively structured thereafter.

With the present invention, the unchangeable spatial arrangement of thetool in relation to the moldable material prescribed in the case of theknown technical solutions by the structural design is no longerapplicable and their mutual alignment is ensured with high precision byascertainment and manipulation of the positional relationships.

The invention is to be explained in more detail below with reference tothe drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a basic representation of an installation for moldingmicrostructures,

FIG. 2 shows a perspective representation of a measuring system for thepositional determination of selected microstructures in a plane,

FIG. 3 shows a device for transporting the measuring system into themolding region and out of this region,

FIG. 4 shows a device for displacing a substrate to be molded inrelation to the tool as an integrated component part of the lowerchamber part of the molding installation,

FIG. 5 shows a plan view of the device according to FIG. 4,

FIG. 6 shows a substrate holder with a substrate resting on it, and

FIG. 7 shows the upper chamber part of the molding installation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the case of the molding installation represented in FIG. 1, a loadframe 1 supports a part 2 which is fixed to the framework and a part 3which is adjustable, to which parts an upper flange 4 and a lower flange5 are fastened. The flanges 4, 5 serve for the securing of oppositelylying chamber parts 6, 7 of a closable chamber, which in the presentexemplary embodiment is designed as a vacuum chamber. Instead of thevacuum chamber, however, a chamber which can be filled with inert gas,for example, is also suitable for molding purposes.

With the cooperation of devices not represented, such as a device forforce measurement, an evaluating and activating unit and a device forpath measurement, the part 3 which is adjustable can be displaced withrespect to the part 2 which is fixed to the framework by a driveintegrated into the frame 1, whereby closing and opening of the chamberis made possible. The evaluating and activating unit controls, interalia, the positioning of the part 2 which is fixed to the framework inrelation to the part 3 which is adjustable and serves with the devicefor force measurement for maintaining a defined force between the part 2which is fixed to the framework and the part 3 which is adjustable.

It is immediately evident to a person skilled in the art that the part 2which is fixed to the framework and the part 3 which is adjustable canbe changed over in their arrangement.

A measuring system 8, to be described in further detail in FIG. 2, isplaced in a removable way onto a mobile framework 9, the underlay 10 ofwhich is fastened to the lower chamber part 7. The mobility of themeasuring system 8 serves the purpose of moving of the latter into themolding region between the two chamber parts 6, 7 when the chamber isopen and out of it again. Hooks 11 provided in the upper region of themeasuring system 8 have at their ends bearing surfaces 12, which areshaped as a three-point bearing in a way corresponding to hemisphericalbearing surfaces 13 on hooks 14, which are attached to the upper flange4. In the hung-in state, a defined positional relationship isestablished between the measuring system 8 and the upper flange 4. Thelower region of the measuring system 8 has hemispherical aligningelements 15, which rest on positioning elements 16 in a three-pointformation during the moving-in and moving-out operation and align themeasuring system 8 on the framework 9 and consequently also in relationto the underlay 10.

The measuring system 8 itself comprises a housing with a bottom plate 17and a top plate 18. This housing can be shielded against externalinfluences by a cladding (not represented) on one or more sides.

An electrically operated mechanical stage 19, which can adjust a stageplate 20 parallel to the bottom plate 17 in two directions of movement21, 22 perpendicular to each other is mounted on the bottom plate 17.

The stage plate 20 serves as a support for a measuring microscope 23,the objective 24 of which has an optical axis O—O directedperpendicularly with respect to the bottom plate 17. An opening, whichcannot be seen in FIG. 2, in the bottom plate 17 ensures the passage ofthe beam necessary for measuring purposes. The mechanical stage 19 alsohas in its central region an opening provided for this purpose. The sizeof the openings ensures unhindered movement of the objective 24 over theentire range of movement in the directions of movement 21, 22.

A defined positioning of the mechanical stage 19 takes place with theaid of the equipment software.

A low overall height of the measuring microscope 23 is achieved by abeam running in a horizontal direction on the image side with respect tothe objective 24. Following the deflection of the optical axis O—O intoa direction parallel to the stage plate, the beam is split into twoseparate optical branches, each of which contains a CCD camera 25 and26, respectively, the position of which is indicated by dashed lines.Different magnifications are used in the optical branches, so that easysearching for microstructures of a viewed object is possible within theimage field of the first CCD camera 25. The magnification of the secondbranch is made such that exact measurement of the positionalrelationships of the structures on the object is possible within theimage field of the second CCD camera 26.

The measuring microscope 23 operates with an illuminating system for abright-field/incident-light illumination. The light is provided by meansof a first fibre-optic cable (not represented) from a suitable firstlight source. In addition, a ring light (not represented), which is fedby means of a second fabric-optic cable (not represented) from a secondsuitable light source, may be attached to the objective 24.Consequently, the use of a dark-field/incident-light illumination isalso possible.

It can be seen more clearly from FIG. 2 that the bearing surfaces 12provided at the hooks 11 have notches 27 aligned in a manner in whichthey are offset in relation to one another by approximately 120°. Of thehemispherical aligning elements 15 attached to the opposite sides of thebottom plate 17, one element is fastened on one side and two elementsare fastened on the opposite side.

A transporting device schematically represented in FIG. 3 comprises theunderlay 10, fastened to the lower chamber part 7, for receiving themobile framework 9 and pneumatic drives 28, 29. The first drive 28serves the purpose of displacing the mobile framework 9 on the underlay10 from a parking position 30, lying outside the molding region, into anintermediate position 31, which already lies within this region.

The second drive 29 undertakes the transport from the intermediateposition 31 into a hanging-in position 32, in which the measuring systemcan be hung by its hooks 11 onto the hooks 14 of the upper flange 4.

The molding installation contains in the lower chamber part 7, as afurther subdevice, a displacing device 33 according to FIGS. 4 and 5,with which a substrate 34 to be molded can be adjusted in a planeperpendicularly with respect to the closing direction of the chamberwith respect to a tool denoted in FIG. 7 by 46.

Of two sliding plates 35, 36 which lie one on top of the other and aremovable in relation to each other parallel to the plane of the substratedisplacement, stops 37 are provided for the upper sliding plate 36 andare respectively brought by pneumatic cylinders 38 up against a driveunit 39, serving as a position encoder, on the sliding plate 35.Suitable measuring means (not represented) monitor the positions set bythe drive unit 39. The upper sliding plate 36 supports a lower part 40of a heating and cooling unit, which is necessary for the molding and onwhich a substrate holder 41 is mounted. On the substrate holder 41, thesubstrate 34, which, as can be seen from FIG. 6, comprises a supportinglayer 42 and a moldable material 43, can be fixed with the aid of springelements 44. Lateral stops (not represented) may be additionallyprovided. Usually, the supporting layer 42 consists of a structuredmaterial, such as for example a photolithographically structured ceramicplate or a structured printed-circuit board.

If the material 43 is to be molded on both sides, it is possible toreplace the supporting layer 42 by a further tool.

The upper sliding plate 36 has the additional task of forming the lowertermination of the chamber. If the chamber is operated under vacuumconditions, forces for which there are no counteracting forces act onthe upper sliding plate 36 due to the atmospheric pressure. To excludean undesired deformation of the chamber and to ensure a defined relativeposition of the two sliding plates 35, 36 in relation to each other, theupper sliding plate 36 can be pneumatically clamped to the lower slidingplate 35. The force necessary for this is produced by four pneumaticcylinders 45, fastened to the lower sliding plate 35.

The force available at the thrust rods of the pneumatic cylinders 45 istransferred by four clamping plates 46 onto the upper sliding plate 36.

According to FIG. 7, the upper chamber part 6 contains the tool 46 whichis necessary for the molding and which is enclosed on itscircumferential surface by a cylindrical tool holder 47, fastened on abase plate 48 in a sealed manner. The base plate 48 is in connectionwith the upper part 49 of a heating and cooling unit, which is fastenedto the upper flange 4.

In the present exemplary embodiment, a demolding device 50 isadditionally contained in the upper chamber part 6, of which device anannular demolding tool 51, which can be displaced parallel to thedirection of the adjustment of the chamber parts 6, 7, encloses the toolholder 47. With an annular groove 52 machined into the base plate 48 andthe lateral surface of the tool holder 47, the demolding tool 51 forms apressure chamber into which a feed channel for compressed air is ledthrough the base plate 48. The demolding tool 51, which has on its endface a projection 53 with a peripheral seal 54, bears in a sealed manneragainst the lateral surface of the tool holder 47 and against the outercylindrical surface of the groove 52. This ensures that the demoldingtool 51 can operate like the piston of a pneumatic cylinder. The rangeof movement is limited in one direction by the base plate 48 and in theother direction by stops (not represented). Restoring springs (notrepresented) serve the purpose of bringing the demolding tool 51 backinto its position of rest after the feeding of compressed air has beenended.

The demolding device 50 serves the purpose of separating the substrate34 from the tool 46 after the molding process, by the substrate 34 beingpressed against the substrate holder 41 by the demolding tool 51, whileat the same time the chamber is open. In addition, compressed air forassisting the detachment can be introduced into the space formingbetween the substrate 34 and the tool 46. For this purpose, the spaceforming is sealed towards the outside.

The hooks 14 with the hemispherical bearing surfaces 13 are fastened tothe upper flange 4 in a manner in which they are respectively offset by120°, so that only one is completely visible. An outwardly sealing sidewall of the chamber is subdivided into wall parts 55, 56, of which thewall part 55 is attached to the flange 4 and the wall part 56 forclosing the chamber comes to rest on a sealing outer region of the lowerchamber part 7. Both wall parts 55, 56 are adjustable themselves inrelation to each other in the direction of the adjustability of thechamber parts 6, 7, whereby the height of the chamber is variable.

When the structures of the tool 46 are being molded into the moldablematerial 43, heating and cooling outputs are introduced into thechamber. In order to achieve the accuracies necessary for the adjustedmolding operation, in the present exemplary embodiment important partsof the measuring system 8, of the displacement device 33 and of theupper chamber part 6 are provided with channels for atemperature-controllable fluid, preferably water.

For instance, the flange 4 of the upper chamber part 6 has coolingchannels 57 passing through it. The hooks 14 are also designed ascooling blocks and contain corresponding channels. Temperature-controlblocks 58 are attached to the bottom plate 17 and to the top plate 18 ofthe measuring system 8. The sliding plates 35, 36 have suitable bores 59for temperature control.

In addition to the function already mentioned, the evaluating andactivating unit has a variety of further tasks, such as controlling themechanical stage 19 and the measuring system 8, monitoring the positionsof the two directions of movement 21, 22 of the mechanical stage 19,evaluating the information from the first and second CCD cameras 25, 26with suitable image processing algorithms and controlling all thepneumatic units as well the drive units 39 and the position monitoringof the latter. The evaluation of the information from the first andsecond CCD cameras 25, 26 can be performed, for example, by theexecution of the positioning and molding operation being carried outfully automatically. The evaluating and activating unit may,furthermore, be designed in such a way that the automatic finding ofstructures within the images of the CCD cameras 25, 26 is possible.

The following procedure serves for transferring the structures presenton the tool 46 to the moldable material 43 with an exactlypredeterminable locational position.

Once the substrate 34 has been put in place and fixed on the substrateholder 41 with the aid of the spring elements 44, the chamber is closedby adjusting the chamber parts 6 and 7 towards each other andsubsequently evacuated.

During this operation, the adjustable part 3 is moved until the tool 46and the moldable material 43 are touching. The height of the chamber isthereby adapted to the thickness of the moldable material 43 by theadjustability of the wall parts 55, 56 with respect to each other.Subsequently, a heating of the tool 46 and the moldable material 43commences with the aid of the two parts 40 and 49 of the heating andcooling unit. The force effect brought about by a further adjustment ofthe part 3 and in cooperation with the evaluating and activating unitand also the device for force measurement has the effect of producing adefined pressing force between the substrate 43 and the tool 46, so thatthe intended structure transfer takes place. Once the transfer has beencompleted, a cooling phase and a subsequent admission of air to thechamber follow. With the aid of the demolding device 50, the moldablematerial 43 is separated from the tool 46.

For checking the result of the molding operation, the two chamber parts6, 7 are brought to a distance at which not only is the measuring system8 brought with the aid of the transporting device from the parkingposition 30 into the hanging-in position 32 suitable for measurement butit is also possible for the substrate 34 to be put into place andremoved.

The measuring system 8 located in the parking position 30 together withthe mobile framework 9 is moved between the two chamber parts 6, 7 intothe intermediate position 31 by activating the first pneumatic drive 28.Subsequently, the lower chamber part 6 is adjusted towards the upperchamber part 7, whereby the transporting device and the measuring system8 are moved along with it. The three hooks 11 fastened to the measuringsystem 8 enter the upper chamber part 7 until the notched bearingsurfaces 12 are located above the bearing surfaces 13 fastened to thethree hooks 14. The intermediate position 31 is chosen such that thehooks 11 and 14 do not collide with one another.

With the aid of the second pneumatic drive 29, the mobile framework 9together with the measuring system 8 is brought into the hanging-inposition 32, in which the bearing surfaces 12, 13 are located directlyone above the other in the vertical direction. By lowering the lowerchamber part 6, the hanging-in operation is completed.

Aligned in a defined manner with respect to the tool 46 and in all sixlines of freedom, and decoupled from the mobile framework 9, themeasuring system 8 now assumes a measuring position.

If, after carrying out measurements, the measuring system 8 is intendedto be moved out again from the region between the two chamber parts 6,7, the mobile framework 9 must firstly be brought into the hanging-inposition 32 again. The lower chamber part 6 is adjusted together withthe mobile framework 9 towards the upper chamber part 7, until thealigning elements 15 come to bear against the positioning elements 16.The coupling of the bearing surfaces 12, 13 is discontinued, after whichthe two surfaces lie one above the other in the vertical direction.While the second pneumatic drive 29 undertakes the transport into theintermediate position 31, the first pneumatic drive 28 brings the mobileframework 9 with the measuring system 8 into the parking position 30.When it is moved out into the parking position 30, the elements to betransported must be in a sufficiently large free space.

Since a direct ascertainment of the positional relationships between thetool 46 and the substrate 34 is not possible during the moldingoperation, it becomes necessary to ascertain the location coordinates ofmolded microstructures 60 on the moldable material and/or of alreadyexisting marks 61 on the supporting layer 42 before and after themolding operation in a trial molding operation preceding the actualmolding operation. The respective substrate 34 can then be brought intothe required position with respect to the tool 46 on the basis of thelocation coordinates ascertained, so that positioned molding can beachieved. Structures present on the tool 46 can be transferred to themoldable material 43 with an exactly predeterminable locationalposition.

For carrying out measurements on the microstructures 60, the marks 61 oron existing marks 62 on the substrate holder 41, the measuringmicroscope 24 is firstly brought into the measuring position andsubsequently moved with the aid of the mechanical stage 19 over thesupporting layer 42 in the directions of movement 21, 22, until themicrostructures 60 to be measured, the marks 61 or the marks 62 aresensed. Focusing takes place by raising and lowering the lower chamberpart 6. The data of the images recorded by the microscopic imageformation of the CCD cameras 25, 26 are made available to the evaluatingand activating unit for further processing, in particular for thepositioning of the substrate 34 with the aid of the displacing device 33required for locationally exact molding.

For the positioning operation, the clamping between the upper and lowersliding plates 35, 36 brought about by the four pneumatic cylinders 45and the clamping plates 46 is discontinued. It is advantageous if thepositional relationships between the marks 61 on the supporting layer 42and the microstructures 60 of the tool 46 copied into the moldablematerial 43 are prescribed. The evaluating and activating unit is thencapable of calculating the positions to be set of the substrate 34fastened on the substrate holder 41, with the assistance of the locationcoordinates ascertained in the trial molding operation for themicrostructures 60 and for the marks 61, and if need be for the marks62, and of performing the activation of the drive units 39. The driveunits 39 define by their setting the position into which the stops 37for the upper sliding plate 36 are to be brought by the force of thepneumatic cylinders 38, whereby the substrate holder 41 with thesubstrate 34 is positioned in the translational coordinates and in theangular position with respect to the tool 46 in a plane parallel to thesurface of the sliding plates 35, 36. Following the deactivation of thepneumatic cylinders 38, the position of the upper sliding plate 36 isinitially maintained by the dead weight, before the restored clampingbetween the upper and lower sliding plates 35, 36 stabilizes theposition of the upper sliding plate 36.

The set position can be checked by determining the coordinates of themarks 61 on the supporting layer 42 once again in the way alreadydescribed. If appropriate, a repeated position setting with thedisplacing device 33 is required.

With the solution according to the invention, structures or objectscontained on a support can be transferred with very high accuracy topredeterminable locations in a plastically deformable material. This isachieved by measurements of the location coordinates of the transferredstructures or objects or of existing structures in the region of thetransporting area and subsequent positioning of the region to bestructured with respect to the support according to the measuredlocation coordinates.

The measurements in the region of the transfer area must take place atsuch locations that the sensing of all the displacements having aneffect on the location coordinates of the transferred structures orobjects in a direction perpendicular to the direction of the transfer ofthe structures or objects is ensured.

In the present exemplary embodiment, the following procedures for theexecution of the positioned molding operation are envisaged for thispurpose:

In the simplest form, the basic principle, firstly a first substrate 34is molded (rough molding) and then the position of the moldedmicrostructures 60 in the moldable material 43 is measured. Once themarks 61 on the supporting layer have been measured with the aid of thedisplacing device, further substrates 34 to be processed are broughtinto the position in which the structures of the tool 46 are copied in asubsequent molding operation into the moldable material 43 in a defineddistance-based relationship with respect to the marks 61. Thecoordinates of the structures 60 of the tool 46 copied into the moldablematerial 43 are known from the trial molding operation.

A first refinement of the positioned molding operation envisagesmeasuring the positions of the marks 61 on thee supporting layer 42before and after the trial molding of the first substrate 34 and theposition of the molded microstructures 60 in the moldable material 43and using the measurement results for aligning the further substrates 34to be processed. This in turn involves firstly a determination of thelocation coordinates of the marks 61 as a basis for the requiredpositioning with the displacing device 33. It is also advantageous ifthe structure positions in the supporting layer 42 and in the moldablematerial after the molding operation are sensed for the respectivelyfollowing molding operation. This first refinement of the positionedmolding achieves the effect that positional deviations of the substrate34 with respect to the substrate holder 41 occurring in the moldingprocess due to heating, cooling and molding do not act as defects.

In a repeated refinement of the molding process, the positions of themarks on the substrate holder 41 are also included. The marks 62 arealready measured before the first substrate 34 is put in place. Thepositions of the marks on the substrate layer 42 before and after themolding operation and the position of the molded microstructures 60 inthe moldable material 43 are then measured.

In the case of the further substrates 34 to be processed, the positionof the marks 62 on the substrate holder 41 before the substrate 34 isput into place and the position of the marks of the supporting layer ofthe substrate 34 put into place are measured. Subsequently, positioningand molding are performed. After the molding operation, the positions ofthe marks in the supporting layer 42 and in the moldable material aresensed for the respectively following molding operation. The repeatedrefinement of the molding process achieves the effect that drift effectsbetween the upper chamber part 6 and the measuring system 8 fixed to itduring a measurement, on the one hand, and the lower chamber part 7 withthe positioning system 33 fastened to it, on the other hand, do not actas defects.

While the foregoing description and drawings represent the presentinvention, it will be obvious to those skilled in the art that variouschanges may be made therein without departing from the true spirit andscope of the present invention.

What is claimed is:
 1. A device for transferring microstructures from atool to a substrate which is to be structured comprising: supports forthe tool and the substrate which can be adjusted in relation to oneanother in a direction resulting in an alteration of the distancebetween the tool and the substrate; a measuring system for measuringselected locations in at least one measuring plane, in relation to whichthe direction of adjustment of the supports is directed vertically; saidmeasuring system being able to be pushed in between said supports and,when in a measuring position, being in a fixed spatial relationship withthe tool; and said substrate being able to be displaced parallel to themeasuring plane for alignment with respect to the tool.
 2. The deviceaccording to claim 1, wherein the support for the tool is contained in afirst chamber part and the support for the substrate is contained in asecond chamber part of a closable chamber, in which the transfer of themicrostructures takes place by molding.
 3. The device according to claim2, wherein the chamber is designed as a vacuum chamber.
 4. The deviceaccording to claim 2, wherein the chamber can filled with inert gas. 5.The device according to claim 1, wherein the measuring system includesvarious optical branches with image fields of different sizes, themagnification of a first optical branch permitting easy searching forthe locations to be selected and that of a second optical branchpermitting exact measurement of the selected locations in the measuringplanes.
 6. The device according to claim 5, wherein a transportingdevice which contains different drives for positions to be moved to oneafter the other is provided for the pushing in of the measuring system,a first drive undertaking the transport from a first position outsidethe chamber into a second position in the opened chamber and a seconddrive moving the measuring system into a position aligned in relation tothe tool.
 7. The device according to claim 6, wherein a device fordisplacing the substrate with respect to the tool is contained in thesecond chamber part and includes two sliding plates which lie one on topof the other, are movable in relation to each other parallel to theplane of the substrate adjustment and of which an upper sliding plateserves as a chamber-closing element.
 8. The device according to claim 7,wherein the upper sliding plate can be clamped to the lower slidingplate.
 9. The device according to claim 8, wherein the upper slidingplate supports a first part of a heating and cooling unit, on which asecuring means for the substrate is fastened.
 10. The device accordingto claim 9, wherein, for changing the height of the chamber, the chamberhas side wall parts which provide a seal towards the outside and arethemselves adjustable in relation to one another in the direction of theadjustability of the chamber parts.
 11. The device according to claim10, wherein the tool is enclosed on its circumferential surface by acylindrical tool holder, which is fastened in the first chamber part toa plate-shaped body.
 12. The device according to claim 11, wherein theplate-shaped body is in connection with a second part of a heating andcooling unit.
 13. The device according to claim 12, wherein the toolholder is enclosed at the lateral surface by a demolding tool, which isdisplaceable with respect to the tool holder in the direction of themutual adjustability of the supports for removing the substrate from thetool following the transfer of the microstructures.
 14. The deviceaccording to claim 13, wherein the measuring system, the displacingdevice and the first chamber part contains channels for atemperature-controllable fluid.
 15. The device according to claim 14,wherein, for establishing the fixed spatial relationship between themeasuring system and the tool, hooks for hanging on correspondinglyshaped hooks of the first chamber part are fastened to the measuringsystem in the upper region of the latter.
 16. The device according toclaim 14, wherein the substrate comprises a supporting layer and amoldable material applied to the latter.
 17. The device according toclaim 14, wherein a tool for transferring structures into the moldablematerial is applied to the supporting layer.
 18. A method fortransferring microstructures from a tool to a substrate which isstructured, with supports for the tool and the substrate which can beadjusted in relation to one another in a direction resulting in analteration of the distance between the tool and the substrate comprisingthe steps of: ascertaining a positioning, required for the locationallyexact transfer of the microstructures, of the substrate which is to bestructured with respect to the tool in a plane in relation to which thedirection of adjustment of the supports is directed vertically bycorrection values for the positioning, by the distance of themicrostructure from a mark on the substrate, being formed from measuredstructure positions of transferred microstructures on a first structuredsubstrate for at least one further substrate to be structured and;transferring the microstructures.
 19. The method according to claim 18,wherein, on the first substrate the positions of the marks areadditionally ascertained before and after the transfer of themicrostructures for forming correction values for the positioning. 20.The method according to claim 18, wherein the positions of marks on thesubstrate holder are additionally determined before a substrate isplaced onto the substrate holder in order to serve as correction values.21. The method according to claim 19, wherein, after the molding of eachsubstrate, the positions of the molded microstructures and of the marksare determined as correction values for the positioning of the substratewhich is to be respectively structured thereafter.